Why not try HDPE idlers or idlers with synthetic rubber sleeve. ■

With sulphuric acid, natural rubber (NR) is better than synthetic (SBR), and EDPM is better than NR. ■

My chemistry is a bit rusty, but will handling solid sulphur in normal atmospheric conditions produce actually produce sulphur dioxide or hydrogen sulphide?? ■

You are correct there is no danger in handling sulpher in normal ambient conditions. But danger is from sulpher particles adhering to crevises and getting oxidised over a period of time. ■

Hi All,

I would add my experience with regards to idler roll construction and the negatives I have experienced over decades of use. I have been involved with many 'Experiments' with corrosion and wear factors in idler rolls in many environments. The other factors also included making the rolls FRAS [Fire Resistant Anti Static] for underground coal and metalliferous mines, and especially where sulphur is present. Galvanizing of roll tubing before welding assembly of the roll found it corroded at a much higher rate at the welded end disc area and the rolls were failing within weeks. We tried carbon black additives to the HDPE & UHMW and it flat spotted quickly due to the HDPE/UHMW being too slippery with not enough friction to keep the rolls rotating. Other UHMW and other 'Plastics' coated rolls as well as Aluminium shell/sleeves also do not have the natural friction to keep the roll rotating and 'Flat Spotting' is a roll life shortening eventuality. Be aware that sulphur also creates an acidic base when in contact with moisture in the atmosphere which attacks most steels and many 'Plastic' products, including galvanized surfaces. Others have tried many additives [tungstun chip / sand / glass bead etc in paint.] to get frictional contact with paint corrosion protection and these rolls again suffered in buildup from 'carry-back'. For an idler roll to perform well, it must have a natural friction surface to belting cover contact to keep the rolling of the roll element but also should be able to refrain from 'carry-back' buildup on the roll surface. The best roll I have found is the old style 'Link-Belt' roll which has a electrostatic applied polymeric Corvel Grey enamel paint baked at high temperature. These rolls do not seam to be affected by the sulphur based acidic products and the wear is very good and the 'carry-back' does not pick up or appear to be a note-worthy issue.

I know that this seams to be pushing the barrow for 'Link-Belt' but I am sure that the other manufacturers would also use a similar type of roll finish. ■

Visit www.innoveyorusa.com: titanium enriched PVC idlers, MSHA approved, no exposed steel, CEMA D & E and composite frames, CEMA D. ■

I read a litter further, yes the coefficient of friction for:

* HDPE 0.175 +/-

* t-PVC idler 0.45 +/- (www.innoveyorusa.com)

* Steel (1018) 0.45 - 0.47 +/- ■

Dear Sir,

We recommend to use HDPE idler. The HDPE idler features in anti-corrosive, light weight, power saving, water proof, dust proof, good dynamic balance and low decibel. We have been engaged in the field of plastic roller for almost 25 years and we're confident to satisfy your need. Moreover, the HDPE is a absolutely eco-friendly material.If you're interested in this, feel free contact me at any time.

Thank you & best regards,

Chandler

International Sales & Marketing Dept.

E-Mail: jw@roller.com.tw

Website: www.roller.com.tw

Tel: 886-7-8718126 #209

Fax: 886-7-8718128

Mobile Phone: 886-939-540-608

Add: No.17 Chang Tai Street, Hsiao Kang, Kaohsiung, Taiwan

Jim Way Enterprise Co., Ltd ■

Originally Posted by debashisde

For handling of granular sulphur that I am now designing we specified idlers to be galvanised which I am not confident to be the best solution as zinc may even enhance the corrosion in presence of sulphur which may generate even sulphur di oxide or H2S. Need your best suggestion. Any painting will help better.

regards

D De

May bee, my new rollers/idlers will be you a help. This patented rollers are made out of very low-cost recycling full material with a steel-, or inox-axle and the same bearings and seals like then in steel rollers. Such rollers have many other fine features for the conveyors, because they are not out of tubes, instead they are out of "FULL-MATERIAL"!

Best regards, P. Blaha Rosenstr.5 85609 Aschheim near Munich/ Germany ■

Originally Posted by debashisde

For handling of granular sulphur that I am now designing we specified idlers to be galvanised which I am not confident to be the best solution as zinc may even enhance the corrosion in presence of sulphur which may generate even sulphur di oxide or H2S. Need your best suggestion. Any painting will help better.

regards

D De

the idlers may be covered with a 3mm thick wear resistant rubber. This will give prtection agaist corossion from sulpher and its derivatives and will also provide the necessary friction. other exposed surfaces of the rollers may be painted with Epoxy or rubber paints to protect from corrosion.

Rajagopal ■

Originally Posted by Rajagopal

the idlers may be covered with a 3mm thick wear resistant rubber. This will give prtection agaist corossion from sulpher and its derivatives and will also provide the necessary friction. other exposed surfaces of the rollers may be painted with Epoxy or rubber paints to protect from corrosion.

Rajagopal

If I don't get your E-MAIL, I cannot send you the catalogs of my new innovation

RY-FULL-Plastic Rollers made very low-cost out of RECYCLING-PLASTIC.

We can do in my Rollers the same, p.ex. the bearings, seals like on the steel rollers.

If you need a roller like INOX, I will take an inox-axle and all other tiles are made out of plastic - also the bearing in INOX Quality if you pay for it.

Best regards Blaha, Peter Rosenstr.5 D-85609 Aschheim near Munich ■

Please visit our website to view some possible solutions to your problem. Please state that you was refered by Brian Rogers.

www.lasercladding.com ■

Hi all,

Since I last posted a reply, I have patent applied for a new style of conveyor roll which I have been working on for more than 23 years. The innovation allows fast turnaround of orders for idler rolls where minimal inventory stock is required to be kept and each roll in a production line run can be assembled in seconds. It also allows for various shell tubing to be used in the construction and sulphur or other corrosive products can be accommodated by changing the shell tubing composition. Each roll is close to or exceeds ' Weigh Scale' specifications without further machining or balancing. I have added the dot point specifications FYI (For Your Information).

NOTE:-****************I have many of the major manufacturing companies vying for the IP so they can control the market as each has said, in their words, " that it will put the other manufacturers out of the running to compete with price and quality". The IP is going to be offered to the manufacturer that comes up with the best outcome for me, whether it be purchase outright, lump sum and royalties or other proposals. Everything is open for negotiation. *

------------------------------------------

********

******** The Innovative idler roll has a, press in and full mass swaging into tubing, head somewhat similar, but different, to the old Moore [Link Belt aluminium head roll] ex BHP Newcastle Australia around the 1920s. The head is one for each roll diameter to cover every type of roll in that diameter range. The head mass is lighter than existing rolls that are a through roll shaft-less and has a estimated load rating exceeding a 6411 ball bearing spec. It should cover the CEMA range from B to F and above. The Rim Drag is similar to or less than any other known 6" head. The complete manufacturing plant line equipment would be less than US$175.000.00 .

***************************I would like to thank you for the time in allowing me to introduce you to my revolutionary design for conveyor idler roll heads. The patent application is an 'Improved Stub Axle TechnologyIdler Roll'. Patent application 2009900370. A confidentiality agreement is required should you require further detail.

The concept allows for:-

1/ Rolls Diameters from 3.5" to >9".

2/ Just one head for each particular roll diameter. Approximately 8 roll heads

in total.

3/ Heads are disposable or reuseable.

4/ Heads available in various materials, steel, stainless, aluminium etc. on

request.

5/ Each roll head suits all applications Ie:- (i) Impact (ii) Trough (iii)

Return (iv) Catenary (v) Single End Mount (vi) ALL manufacturers Frame Mounts

Slots (vii) Any Special Mount Point. This is achieved by Slip-on Adaptors

with/without extension handles for tracking/training in returns.

6/ There is only one bearing pack.

7/ One head Outside Diameter Profile to accommodate all shell tubing from 3mm

to 6.4mm or larger.

8/ Eight (8) only Head sizes to suit 89mm, 104mm, 114mm, 127mm, 152mm, 178mm &

194mm plus other or over size diameters can be specially configured.

9/ *Reduced bearing with seals inventory to one.

10/ The Bearing pack design exceeds 6411specifications. Ball or Taper Roller.

Angular deflection of shaft to head remains minimal under all load

conditions.

11/ Head sizes just varies the OD with a Press in & full mass Swage designed single

cross-sectional profile.

12/ Adaptors are Slip-on to suit every mount point or Link for catenary.

13/ Shaft Adaptors suit to >45mm diameter with Catenary Link built in for

convenience.

14/ *Broached width sizes from 1/2"(12.7mm); 9/16"(14mm); 3/4" (19mm);

7/8"(22mm); 1 1/4" (32mm) or any specials.

15/ *Stub Axle/Bearing pack can be replaced.

16/ Seal, dual lipped moulded to lock collar can be replaced.

17/ Bearing Pack is concealed for protection.

18/ Frustoconical weather seal is replaceable.

19/ Leather or felt seal, internal in Frustoconical Deflector Weather Seal,

wiper seals available for special electrostatic (alumina).

20/ *Manufacture of roll:-

********(a) Simple shell tube length cutting machine.

********(b) A full collett lathe to prepare ends for concentricity, to external

tube outside diameter, for head fitment. Also forms the roll to weigh scale

tolerances in most cases without machining the OD and balancing.

********(c) A dual stroke (Internal and external co-axial operation) 20tonne

Press.

****** *(d) Paint booth as required if not in S/S.

********I look forward to any comments for this innovation and to hearing from

you.

********Once again, thank you for your time.

eMail:- tecmate@bigpond.com ■

We have a sprayable application that you might be interested in. It offers excellent corrosion protection and can meet strict thickness specifications. If you are interested please contact me for more information. ■